US 2004/024089A1 relates to the use of epoxypolysiloxanes modified with oxyalkylene ether groups as additives for cationically radiation-curing coatings and discloses a coating, printing ink or paint varnish that is curable cationically by radiation, which comprises a compound that contains epoxy, oxirane and/or vinyl groups and an additive comprising at least one epoxypolysiloxane which is modified with oxyalkylene ether groups and contains attached to an Si atom of the epoxypolysiloxane, at least one group of the formula —R3—O—(CnH(2n-m)R4mO—).xR5 (I) in which R3 is a divalent, unsubstituted or substituted alkyl or alkylene radical, n is 2 to 8, m is 0 to 2n, x has a value of 1 to 200, and R4 stands for identical or different alkyl radicals having or for identical or different, unsubstituted or substituted phenyl radicals, R5 is a hydrogen, an unsubstituted or substituted alkyl radical, an acyl radical or a radical —O—CO—NH—R6, in which R6 is an unsubstituted or substituted alkyl or aryl radical, it being possible for the oxyalkylene segments —(CnH(2n-m)R4mO—) within one oxyalkylene ether radical to be different from one another and for the sequence of the individual oxyalkylene segments —(CnH(2n-m)R4mO—) to be arbitrary, random polymers, or combinations thereof.
WO 01/32789A relates to moisture-curable ink compositions and discloses a cure-on-demand curable ink composition comprising a homogeneous mixture of: at least one of: (a) a compound having 2 reactive silyl groups, and (b) a compound having at least 3 reactive silyl groups; acid generating catalyst; and pigment or pigment chip.
US 2004/050292A1 discloses a photocurable ink for ink-jet recording, comprising an oxetane compound having a substituent at the 2-position of the molecule and US 2004/052967A1 discloses an actinic ray curable composition containing a photo acid generator, and an oxetane compound I represented by the following formula 1
wherein R1, R2, R3, R4, R5, and R6 independently represent a hydrogen atom, a fluorine atom, an alkyl group having from 1 to 6 carbon atoms, a fluoroalkyl group having from 1 to 6 carbon atoms, an allyl group, an aryl group, a furyl group or a thienyl group, and wherein the longer C—O bond distance of the two C—O bond distances in formula 1 is from 0.1464 to 0.1500 nm
Identification documents are used on a daily basis to prove identity, to verify age, to access a secure area, to provide evidence of driving privileges, to cash a check, to make payments, to access an automated teller machine(ATM), to debit an account and so on. Airplane passengers are required to show an identification document (hereafter “ID document”) during check in, security screening and prior to boarding their flight. Since they play a critical role in today's society, it is essential that ID documents cannot be falsified and are tamperproof.
Identification cards and documents, such as driving licenses, national or government identification cards, bank cards, credit cards, controlled access cards and smart cards, carry certain items of information which relate to the identity of the bearer. Examples of such information or variable data include name, address, date of birth, signature and photo of the bearer. The ID cards or documents may in addition carry invariant data, i.e., data common to a large number of cards, for example the name of an employer, the name of the issuing authority and the name of a country.
Ink-jet printing is very suitable for handling variable data, particularly at the issuing locality. Also due to the compactness of ink-jet printers, it has become one of the preferred printing techniques for manufacturing ID documents. Ink-jet printing can be used to assemble identification cards as disclosed, for example, in US 2005/042396A1 using pigmented ink-jet inks for printing the variable data, but it is also possible to use ink-jet printing to introduce security features.
EP-A 1 398 175 discloses an information carrier comprising: a rigid sheet or web support; an opaque porous receiving layer capable of being rendered substantially transparent by penetration by a lacquer, said receiving layer containing a pigment and a binder; an image provided onto and/or in said receiving layer; a cured pattern of a varnish provided onto said receiving layer provided with said image or onto and/or in said receiving layer provided with said image if said varnish is incapable of rendering said receiving layer transparent; and a cured layer of said lacquer provided on said receiving layer provided with said image and said cured pattern of said varnish, said lacquer having rendered said parts of said receiving layer in contact therewith substantially transparent, wherein said cured pattern of said varnish forms an opaque watermark. The watermark ir produced by patternwise penetration of a UV-curable lacquer into a porous opaque receiving layer.
Another security measure used in ID documents is the application of a transparent or translucent layer which is difficult or impossible to remove from the surface of the image-receiving layer, thereby securing the data printed on the image-receiving layer. Such layers can be applied to ID documents using UV-curable liquids as disclosed in EP-A 0189125 and U.S. Pat. No. 5,614,289.
However the availability of cheap digital printing systems such as ink-jet printers also led to a new type of fraudulent action on ID documents. Overprinting and over-labelling of the personalised information, such as the common “photo swap”, method, allows easy and fast abuse of a stolen ID document.
Therefore, it is highly desirable to be able to manufacture ID documents secured against alteration using a simple manufacturing method and a compact apparatus